Geochemical behavior of heavy metals in differents environments in Rodrigo de Freitas lagoon - RJ/Brazil

Abstract

The accelerated urbanisation without a planning, brought several environmental problems to Rio de Janeiro coastal zone, especially in areas such as Rodrigo de Freitas lagoon, which receives a great amount of untreated sewage every day. To assess the nature, potentially sources and extent of heavy metal pollution in the lagoon, sediments from the surrounding streets, from the entrance of the main canal that drains to the lagoon and from the bottom of the lagoon were collected and analysed by a modified selective extraction procedure in order to study the geochemical partitioning and bioavailability of Zn, Cu, Cr, Ni and Pb in these three compartments. The present study verified an increase in the Cu, Pb and Zn concentrations in the north of the Rodrigo de Freitas lagoon. Despite the different levels of oxidation between the sediments accumulated in the streets and in the bottom of the lagoon, the geochemical partitioning of the heavy metals did not show any pattern of variation for the metals, except for the element Cu. No concentrations were found in the soluble phase of samples collected in the surfacial sediments of the lagoon, suggesting no bioavailability of heavy metals.

Biliary and hepatic metallothionein, metals and trace elements in environmentally exposed neotropical cichlids Geophagus brasiliensis

“…1). It is connected to the sea by a narrow channel, although this channel is frequently blocked by sand deposits and, thus, does not allow for free water exchanges, restricting circulation and water renewal [9]. Because of this, water stratification occurs, with the deeper water layer frequently becoming anaerobic and rich in hydrogen sulfide (H 2 S) gas, due to oxidation of the organic matter present in the bottom of the lagoon.…”

“…These characteristics present favorable conditions for pollutant accumulation in the lagoon's substratum. In addition, the lagoon illegally receives untreated domestic sewage enriched in organic matter, detergents, synthetic organic material and metals and trace-elements on a daily basis, and is also exposed to huge hydrocarbon and metal and trace-elements inputs originated from incomplete combustion of fossil fuels, due to the approximately 190 thousand vehicles that pass through the area each day [11], as well as the presence of several surrounding gas stations [9]. Fig.…”

Geochemistry of intertidal sediment pore waters from the industrialized Santos-Cubatão Estuarine System, SE Brazil

“…The occupation of coastal areas by industrial and urban activities has been recognized as the main cause of sediment contamination by potentially toxic trace elements in many regions (e.g., Rebello et al 1986, Faria and Sanchez 2001, Molisani et al 2004, Pereira et al 2007, Fonseca et al 2011. This relationship has been systematically observed in the Santos-Cubatão estuarine system (São Paulo State, SE Brazil).…”

Source Identification, Bioavailability, and Risk Assessment based on Geochemical Fractionation of Heavy Metals Pb, Cu, and Zn in Surface Sediments of Kelabat Bay, Bangka Island

“…Heavy metals that flow to the marine environments due to human activities show high mobility and are associated with carbonate, oxide, hydroxide and sulfide sedimentary phases (Bastami et al, 2017). Research on geochemical fractionation of heavy metal has been carried out widely in coastal and marine areas such as the Malacca Strait (Yap et al, 2003), Persian Gulf (Karbassi et al, 2005), Jakarta Bay (Takarina et al, 2008;Arifin and Fadhlina, 2009), Berau-East Kalimantan Delta (Situmorang et al, 2010), Rodrigo de Freitas-RJ / Brazil Lagoon (Fonseca et al, 2011), and Banten Coastal Waters (Takarina et al, 2013).…”