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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

DistribuiÃÃo de Mercurio (Hg) em Sedimento, Ãgua e Biota na RegiÃo de Influencia dos Efluentes da Carcinicultura na Gamboa do Cumbe â Rio Jaguaribe - Cearà â Brasil / Distribution of mercury (Hg) in Sediment, Water and Biota in the Region of Influence of effluents from the shrimp in the Cumbe Gamboa - Rio Jaguaribe - Cearà - Brazil

Breno Gustavo Bezerra Costa 09 February 2009 (has links)
A bacia hidrogrÃfica do Rio Jaguaribe, localizada no Estado do CearÃ, ocupa uma Ãrea de em torno de 80.000 km2, a sub-bacia do Baixo Jaguaribe tem Ãrea de drenagem de 6.875 km2, sendo esta correspondente a 4,64% do territÃrio cearense. A regiÃo estuarina do Rio Jaguaribe à dominada por florestas de manguezal que ocupam 215,5 ha, particularmente no canal de marà da Gamboa do Cumbe. Estando na regiÃo Ãrea implantada a maior Ãrea de produÃÃo de camarÃo em cativeiro do estado, ocupando 1.316 ha em viveiros cerca de 50% do total de todo o Estado do CearÃ. A quantificaÃÃo de mercÃrio (Hg), na Ãgua e em sedimento (superficial e testemunhos sedimentares) ao longo de toda a Gamboa do Cumbe mostrou valores variando de 6,3 a 32,1 ng/l (14,4  8,4), 1,1 a 23,5 ng/l (7,0  7,8), 3,2 a 15,0 ng/l (7,4  3,9), para o Hg total, dissolvido e particulado na Ãgua respectivamente. No sedimento as concentraÃÃes variaram de 1,6 a 10,3 ng/g (4,7  2,9) e 1,9 a 16,2 % (6,7  4,9) respectivamente para a concentraÃÃo de Hg e percentual de matÃria orgÃnica. A concentraÃÃo de Hg em peixes coletados na regiÃo variaram de 4,3 â 37,0 ng/g (9,9  9,0) em Sphoeroides testudineos e 9,7 a 66,1 ng/g (31,8  14,4) Cathorops spixii. Com a obtenÃÃo destes dados pÃde-se definir a Ãrea preferencial de deposiÃÃo e acumulaÃÃo de Hg e a forma dissolvida mostrou-se a predominante exportada. Aquacultura promove alteraÃÃes significativas das cargas de Hg nos Ãltimos anos baseado nos valores da concentraÃÃo de Hg nos perfis sedimentares. O Hg proveniente da aquicultura à 156,4 kg.ano-1, na sua maioria associados ao MPS sendo transportado para a regiÃo estuarina adjacente e depositado na Ãrea da Gamboa do Cumbe. / The Jaguaribe River basin, located in State CearÃ, occupies an area of about 80,000 km2, wher as the sub-basin of the Lower Jaguaribe River has a drainage area of 6,875 km2, equivalent to 4.64% of the stateâs area. The estuarine region of the Jaguaribe River is dominated by mangrove forests that occupy 215.5 ha, particularly in the tidal channel of the Gamboa do Cumbe. In this area it is located the largest area of shrimp production in captivity in the state, with 1,316 ha of pond area around 50% of the entire aquaculture area of the state of CearÃ. The quantification of mercury (Hg) in water and sediments (surface and sedimentary profile) along the Gamboa do Cumbe showed values ranging from 6.3 to 32.1 ng / l (14.4  8.4) , 1.1 to 23.5 ng / l (7.0  7.8), 3.2 to 15.0 ng / l (7.4  3.9), or total Hg, dissolved and particulate Hg respectively. In sediments concentrations ranged from 1.6 to 10.3 ng / g (4.7  2.9) and 1.9 to 16.2% (6.7  4.9) for Hg and organic matter respectively. The concentration of Hg in fish collected in the region ranged from 4.3 to 37.0 ng / g (9.9  9.0) in Testudines sphoeroides and from 9.7 to 66.1 ng / g (31.8  14 , 4) in Cathorops spixii. These data made possible to define the area of preferential deposition and accumulation of Hg and that the predominant form of Hg export is dissolved Hg. Aquaculture, seems to have promoted significant changes in Hg loads in recent years based on records of Hg concentration in sedimentary profiles. Hg of burden from aquaculture to the region is about 156.4 kg.ano-1, mostly associated with TSS transported of the adjacent estuarine region and is stored in the sediment of the deposition area of Gamboa do Cumbe.

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