Postgraduate Program in Geochemistry: Petroleum and Environment (POSPETRO), Geoscience Institute, Federal University of Bahia (UFBA), Rua Barão de Jeremoabo, s/n, 40170-020 Salvador, BA, Brazil; LEPETRO, Excellence in Geochemistry: Petroleum, Energy and Environment, Geoscience Institute, Federal University of Bahia (UFBA), Rua Barão de Jeremoabo, s/n, 40170-020 Salvador, BA, Brazil.
Postgraduate Program in Geochemistry: Petroleum and Environment (POSPETRO), Geoscience Institute, Federal University of Bahia (UFBA), Rua Barão de Jeremoabo, s/n, 40170-020 Salvador, BA, Brazil; LEPETRO, Excellence in Geochemistry: Petroleum, Energy and Environment, Geoscience Institute, Federal University of Bahia (UFBA), Rua Barão de Jeremoabo, s/n, 40170-020 Salvador, BA, Brazil.
Mar Pollut Bull. 2020 Jun;155:111146. doi: 10.1016/j.marpolbul.2020.111146. Epub 2020 May 11.
This article investigates sediments collected from the banks of the Subaé River located in Todos os Santos Bay in the state of Bahia, Brazil, in 2018, twenty-five years after the closing of a former lead alloy processing plant. Ten sediment samples were collected at different points of the course of the river and its estuarine region. Chemometric tools were used to determine geochemical correlations between the organic matter content and concentration of sulfides and potentially toxic metals. The inorganic geochemical variables (enrichment factor [EF]) used in this evaluation were concentrations of the Pb, Cd, Cu, Zn, and Ni. Chemical element analyses were performed using ICP-OES. To assess the interaction between metals and sulfide or metals and organic matter, concentrations of Pb, Cd, Cu, Zn, Ni, sulfide, and the silt-clay fraction constituted the organic geochemical parameters selected to characterize the amount of organic matter present in Subaé River sediment samples, determining the carbon content (%TOC) to compose the matrix of the principal component analysis (PCA) and hierarchical cluster analysis. PCA showed that 88.3% of the samples were representative for assessing correlations between geochemical variables. A tendency toward binding was found among Cu, Cd, Ni, and sulfide, as well as the silt-clay fraction. The concentrations (mg kg) of lead, zinc, and copper were higher in both collection campaigns, ranging from 4.72 to 31.34, 12.76 to 54.24, and 5.34 to 31.37, respectively. Pb and Zn were presented in elemental form when assessed as a function of the pH and Eh of the environment. Except for Cd (EF: 0.51 to 5.49), the other elements exhibited little or no potential pollution in the aquatic environment of the Subaé River.
本文研究了 2018 年从巴西巴伊亚州 Todos os Santos 湾的 Subaé 河河岸采集的沉积物，这是在一家前铅合金加工厂关闭 25 年后进行的。在河流及其河口地区的不同地点采集了十个沉积物样本。使用化学计量学工具确定了有机物含量与硫化物和潜在有毒金属浓度之间的地球化学相关性。该评价中使用的无机地球化学变量（富集因子 [EF]）为 Pb、Cd、Cu、Zn 和 Ni 的浓度。使用 ICP-OES 进行化学元素分析。为了评估金属与硫化物或金属与有机物之间的相互作用，选择 Pb、Cd、Cu、Zn、Ni、硫化物和粉砂-粘土分数的浓度来表征 Subaé 河沉积物样品中存在的有机物量，确定碳含量（%TOC）作为主成分分析（PCA）和层次聚类分析的矩阵组成部分。PCA 表明，88.3%的样品可用于评估地球化学变量之间的相关性。Cu、Cd、Ni 和硫化物以及粉砂-粘土分数之间存在结合趋势。两次采集的 Pb、Zn 和 Cu 浓度（mg/kg）均较高，范围分别为 4.72-31.34、12.76-54.24 和 5.34-31.37。评估环境的 pH 和 Eh 时，Pb 和 Zn 以元素形式存在。除 Cd（EF：0.51-5.49）外，其他元素在 Subaé 河的水生环境中几乎没有或没有潜在的污染。
