Distribution of dissolved, free and labile trace metal species and phosphorus in freshwater systems from the Quadrilátero Ferrífero, Brazil
Description
This dataset is derived from a study aimed to investigate the distribution and lability of trace metals (Co, Cu, Cr, Mn, Ni, Pb and Zn) and P in freshwater systems from a mining area (Quadrilátero Ferrífero, Brazil). The samples were collected at six sampling sites in Upper Doce River catchment in February and October 2014. The physicochemical parameters conductivity, total dissolved solids, pH and temperature were measured in situ using a multi-parameter probe Ultrameter II (Myron L company). The water samples were filtered and ultrafiltered for determination of dissolved (<0.45 µm) and free (<1 kDa) fractions. Diffusive gradients in thin films (DGT) were deployed in situ for determination of the labile fraction of the analysed elements. The species in the free fraction are considered more mobile and potentially bioavailable. Determination of the trace metals and P were carried out by inductively coupled plasma optical emission spectrometry (ICP-OES, Agilent Technologies 700 Series). The data were analysed using a neural network (self-organising maps, SOM) and Spearman’s rank correlation. The concentrations of each fraction of the analysed elements, the file used to perform the SOM analysis and the rank correlations are available in this dataset. The P in the Carmo River occurred mostly in the free and labile fractions and therefore it was considered highly bioavailable. The concentrations of some trace metals such as Co, Cu, Mn, Ni and Zn were high due to natural and anthropogenic factors (e.g., lithology and mining).