Determination of metals concentration in sedimentary profiles from lagoons affected by the tailings from the collapse of the Fundão dam

Abstract

The collapse of the Fundão dam in Mariana released more than 59 million m³ of tailings, which flowed almost 700 kilometers along the Doce river, through the states of Minas Gerais and Espírito Santo, reaching the estuary and into the Atlantic Ocean. In view of all the possible impacts that may have been caused by the environmental accident involving the collapse of the Fundão dam, considered the world's largest socio-environmental disaster involving tailings dams, there is a need for studies that address the level of contamination of terrestrial ecosystems, not only because of their capacity to accumulate chemical elements, but also because they are recognized as possible sources of contaminants. In this segment, this study evaluated the concentrations of metals (Zn, Mn, Cr, Cu, Ni, As, Pb, Ba, Al and Fe) in vertical profiles of sediment samples from three lagoons in Espírito Santo State, affected by the collapse of the Fundão dam. A gravity sampler supplied by the Austrian company Uwitec was used to extract the samples. The sediment samples were subjected to acid dissolution and an inductively coupled plasma optical emission spectrometer (ICP-OES) was used to quantify the metals. Maximum concentrations of iron (235,260 mg kg-1) and arsenic (52 mg kg-1) were obtained in the Areal profile; aluminum (30,270 mg kg-1) and manganese (4,590 mg kg-1) in the Areão profile. The concentrations of Cu, Pb and Zn exceeded the guideline values adopted by the CCME, above which the occurrence of negative effects on biota is likely.

Keywords

• metals
• sediments
• lagoons
• espírito santo
• fundão dam