Associação de hidrocarbonetos alifáticos e metais pesados na zona portuária de Vila do Conde, Barcarena-Pará: concentração, composição e riscos associados ao ecossistema aquático.

Abstract

The contamination on estuarine environments has become a serious problem on different places in ali parts of the world, because your ecological characteristics can be easily changed for the human actions. On this context the port areas need a specific look, because its introduction hydrocarbons from petroleum and heavy metais on this ecosystems. Normally, this contaminants are accumulate on bottom sediment of aqua ecosystems, its sediments was target of so many researches because serves as a testimony, through the years, keep information's, of the different process in aquatic systems. Due to this, the currently thesis becomes into analysis of aliphatic hydrocarbon (n-alkanes) and heavy metais on bottom sediment of a Pará river on port zone of Vila do Conde located on Barcarena city in Pará state. The chromatographed analysis show us that the aliphatic hydrocarbons (n-alkanes) was between the 1,52 - 7,16 mg.kg'1 range and the MCNR was in the 5,21 - 10, 27 mg.kg"1 , what possibly indicated a contamination from petroleum on analyzed sediments. Through evaluation parameters, was clearly evidenced the occurrence of hydrocarbons of recent petrogenic origin in the samples. The spectrometry analysis show the Cd element with 1,68 mg.kg"1 average; Co with 3,08 mg.kg"1 average; Cr with 109,37 mg.kg"1; Cu with 8,13 mg.kg"1 average; Ni with 11,24 mg.kg"1 average; Pb with 122,62 mg.kg"1 average and Zn with 17,74 mg.kg"1 average. The correlation analysis show the significance mainly for Cr, Pb and Zn elements, this is a possible indication of same contamination origin, and the Principal Components Analysis show this fact, where the Zn and Cr had more significance on sediments studied and for local ecosystem on terms of contamination. This analysis shows too that the spots 3 and 5 were the most impacted. Generally the sediments of Pará river are affected for organic and metallic contaminants, and those presenting values above for ERL reference index, to Ni, Cd and Cr metais, and for the ERM index above to the Pb, which can classify the Pará river's sediments, on Vila do Conde port zone, as being contaminated.