Distribution of total dissolved, truly dissolved and DGT-labile trace metal species and phosphorus in freshwater systems from the Quadrilátero Ferrífero, Brazil

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 total dissolved (<0.45 µm) and truly dissolved (<1 kDa) fractions. Diffusive gradients in thin films (DGT) were deployed in situ for determination of the DGT-labile fraction of the analysed elements. The species in the truly dissolved 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 map, SO-Map) and Spearman’s rank correlation. The concentrations of each fraction of the analysed elements, the file used to perform the SO-Map analysis and the Spearman’s rank correlation coefficients are available in this dataset. The results showed that the P in the Carmo River occurred mostly in the truly dissolved and DGT-labile fractions. 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).

本数据集源自一项研究，该研究旨在探究巴西铁四角（Quadrilátero Ferrífero）矿区淡水系统中微量金属（钴Co、铜Cu、铬Cr、锰Mn、镍Ni、铅Pb和锌Zn）及磷P的分布与赋存活性。样本于2014年2月与10月，在多西河上游流域的6个采样点位采集。研究使用多参数探头Ultrameter II（Myron L Company）原位测定电导率、总溶解固体、pH值与水温等理化参数。将采集的水样过滤并超滤，以分别测定总溶解态（<0.45 µm）与真溶解态（<1 kDa）组分。原位部署薄膜扩散梯度（Diffusive gradients in thin films, DGT）技术，以测定分析元素的DGT活性组分。真溶解态组分中的物种被认为迁移性更强且具有潜在生物可利用性。采用电感耦合等离子体光发射光谱法（Inductively Coupled Plasma Optical Emission Spectrometry, ICP-OES，Agilent Technologies 700 Series）完成微量金属与磷的含量测定。数据分析采用神经网络（自组织映射图，Self-Organising Map, SO-Map）与斯皮尔曼秩相关分析。本数据集包含各分析元素各组分的浓度数据、用于SO-Map分析的文件，以及斯皮尔曼秩相关系数。研究结果表明，卡尔莫河（Carmo River）中的磷主要以真溶解态与DGT活性组分形式存在。部分微量金属（如Co、Cu、Mn、Ni与Zn）浓度偏高，这源于自然与人为因素（例如岩性与采矿活动）。