Abstract Barreiro area at Araxa city, Minas Gerais State, Brazil, has been well-known since the 19th century when started the studies of the healing properties for the tuberculosis treatment of the natural mineral waters of the springs Dona Beja (DBS) and Andrade Junior (AJS). In addition, extensive mining activities devoted to the niobum and phosphate fertilizer exploitation have been developed there since the 60's and 70's by different companies, favoring the release of contaminants into the hydric resources of that environment. This paper reports a hydrogeochemical study of surface waters occurring at Barreiro area, comparing their major hydrochemical characteristics with those of other surface waters and rainwater occurring there for identifying possible degradation of their quality due to the anthropogenic inputs associated to the mining activities. The systematic utilized in this approach consisted on the adoption of various experimental steps: hydrochemical analysis by different methods of the several samples collected; hydrochemical data treatment and plotting using traditional statistical tests and geochemical diagrams; use of geochemical data in various sections of six sediment core for calculating the Geoaccumulation Index (Igeo) taking into account sediments outside of Barreiro area for yielding background values, as well as the concentrations reported in the literature for shales and NASC (North American shale composite); leaching experiments of sediment aliquots at room temperature (~20 °C) during about 24 h and using distilled water equilibrated with the atmosphere as leachant for the analysis of the release of barium, chloride, sulfate, phosphate and nitrate. All these protocols allowed an integrated evaluation of the constituents transport at Barreiro area and nearby, improving the knowledge of the environmental impacts associated to the mining activities developed there, responsible by a production of about 20,000 tons/year of ground apatite for phosphate use in agriculture and circa 936 billion metric tons of Nb2O5 ore.

中文翻译：

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巴西米纳斯吉拉斯州阿拉沙市地表水水文地球化学研究

摘要 巴西米纳斯吉拉斯州 Araxa 市的 Barreiro 地区自 19 世纪开始就开始研究 Dona Beja (DBS) 和 Andrade Junior 天然矿泉水的治疗肺结核的治疗特性以来就闻名于世。 (AJS)。此外，自 60 年代和 70 年代以来，不同公司在那里开展了专门用于铌和磷肥开发的广泛采矿活动，有利于将污染物释放到该环境的氢资源中。本文报告了 Barreiro 地区地表水的水文地球化学研究，将它们的主要水化学特征与其他地表水和发生在那里的雨水进行比较，以确定由于与采矿活动相关的人为输入而导致其质量可能下降的情况。在这种方法中使用的系统包括采用各种实验步骤：通过不同方法对收集到的几个样品进行水化学分析；使用传统的统计检验和地球化学图进行水化学数据处理和绘图；使用六个沉积物核心的各个部分的地球化学数据来计算地积累指数 (Igeo)，同时考虑到 Barreiro 地区以外的沉积物以产生背景值，以及文献中报告的页岩和 NASC（北美页岩复合材料）的浓度); 在室温（~20°C）下进行约 24 小时的沉积物等分浸出实验，并使用与大气平衡的蒸馏水作为浸出剂，用于分析钡、氯化物、硫酸盐、磷酸盐和硝酸盐的释放。所有这些协议都允许对 Barreiro 地区和附近地区的成分运输进行综合评估，提高对与在那里开发的采矿活动相关的环境影响的了解，负责生产约 20,000 吨/年的粉状磷灰石用于农业磷酸盐和大约 9360 亿公吨的 Nb2O5 矿石。