Transporte e comportamento geoquímico de metais pesados no estuário Guajarino

Abstract

The Guajarino estuary, which includes the District of Icoaraci and nearby islands, works as a receiver of effluents from industries, shipyards, lumber mills and others, which can cause the accumulation of toxic heavy metals. The determination of the concentration of these metals and the geochemical behavior regarding seasonality and tidal fluctuations will allow the characterization of the compromised areas. Water and sediment samples were collected, since the estuary is also a source of income and subsistence for the population living along its shores. In the water samples physicochemical parameters were analyzed, such as pH, Eh, temperature, electrical conductivity, and dissolved oxygen. In the sediment samples pH and EH were measured and are being analyzed for heavy metals (Fe, Mn, Cu, Pb, Zn, Ni, Cd, Co, Cr, and Hg) through spectro-analytical methods. According to results from the Igarapé Piraiba, the pH of the ebb water is more acidic than the flood water due to the addition of organic substances from logging waste, decreasing the oxidizing power of the water. With ongoing analyses of heavy metals in particulate sediment, bottom sediment, and soils, it is hoped to geochemically correlate areas less affected by anthropic activities with polluted areas.