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).

本数据集源自一项探究矿区（巴西铁四角地区（Quadrilátero Ferrífero））淡水系统中痕量金属（Co、Cu、Cr、Mn、Ni、Pb和Zn）及磷（P）的分布与活性的研究。样本于2014年2月与10月采集自多西河上游集水区的6个采样点位。采用多参数水质检测仪Ultrameter II（迈伦公司（Myron L Company））原位测定了电导率、总溶解固体、pH值与水温等理化参数。对水样进行过滤与超滤处理，以测定总溶解态（<0.45 µm）与真溶解态（<1 kDa）组分。通过原位部署薄膜扩散梯度技术（Diffusive gradients in thin films，DGT），测定分析元素的DGT活性态组分。真溶解态组分中的物种被认为具有更高的迁移性与潜在生物可利用性。采用电感耦合等离子体发射光谱法（ICP-OES，安捷伦科技700系列）对痕量金属与磷进行定量分析。数据分析采用神经网络（自组织映射图，SO-Map）与斯皮尔曼等级相关分析方法。本数据集包含各分析元素各组分的浓度、用于开展SO-Map分析的文件，以及斯皮尔曼等级相关系数。研究结果显示，卡莫河中的磷主要以真溶解态与DGT活性态组分存在。部分痕量金属（如Co、Cu、Mn、Ni与Zn）浓度偏高，这由自然与人为因素（如岩性与采矿活动）共同导致。