Instituto Federal do Triângulo Mineiro (IFTM), Campus Uberaba, Laboratório de Geoprossessamento, Uberaba, MG 38064-790, Brazil.
Instituto Federal do Triângulo Mineiro (IFTM), Campus Uberaba, Laboratório de Geoprossessamento, Uberaba, MG 38064-790, Brazil.
Sci Total Environ. 2022 Dec 10;851(Pt 1):158248. doi: 10.1016/j.scitotenv.2022.158248. Epub 2022 Aug 24.
The present study aimed to investigate the rupture of B1 tailings dam of Córrego do Feijão mine, which drastically affected the region of Brumadinho (Minas Gerais, Brazil). The contamination of water resources reached 155.3 km from the dam site. In the river channel, high concentrations of Mn, Al, As and Fe were detected and correlated to the spillage of the tailings in the river. The presence of the tailings also affected the chlorophyll-a content in the water, as well as the reflectance of riparian forests. With the increase of metal(oid) concentrations above permitted levels, water management authorities suspended the use of Paraopeba River as resource in the impacted areas, namely the drinking water supply to the Metropolitan region of Belo Horizonte. This study aimed to evaluate possible links between tailings distribution, river water quality, and environmental degradation, which worked as latent variables in partial least squares regression models. The latent variables were represented by numerous physical and chemical parameters of water and sediment, measured four times in 22 locations during the rainy season of 2019, in addition to stream flow and to NDVI evaluated in satellite images processed daily. The modeling results suggested a relationship between river flow turbulence and increased arsenic release from sand fractions, as well as desorption of Mn from metal oxides, both representing causes of water quality reduction. They also revealed increasing iron concentrations affecting the forest NDVI (greening), which was interpreted as environmental degradation. The increase of chlorophyll-a concentrations (related with turbidity decreases), as well as the increase of river flows (responsible for dilution effects), seemed to work out as attenuators of degradation. Although applied to a specific site, our modeling approach can be transposed to equivalent dam failures and climate contexts, helping water resource management authorities to decide upon appropriate recovery solutions.
本研究旨在调查科雷戈多费约奥矿 B1 尾矿坝的破裂情况，该破裂事件对布鲁马迪纽地区（巴西米纳斯吉拉斯州）造成了严重影响。水坝破裂导致水资源污染范围达到了距离水坝 155.3 公里的地区。在河道中，检测到 Mn、Al、As 和 Fe 的浓度很高，这与尾矿在河中的泄漏有关。尾矿的存在也影响了水中的叶绿素-a 含量以及河岸林的反射率。随着金属（类）浓度超过允许水平，水管理当局暂停了在受影响地区使用帕拉奥佩巴河作为资源，即在贝洛奥里藏特大都市区停止饮用水供应。本研究旨在评估尾矿分布、河水水质和环境退化之间的可能联系，这些因素在偏最小二乘回归模型中作为潜在变量。潜在变量由水和沉积物的许多物理和化学参数表示，在 2019 年雨季期间，在 22 个地点进行了四次测量，此外还评估了河流流量和每日处理的卫星图像中的 NDVI。建模结果表明，河流流量的紊流与沙粒中砷释放的增加以及金属氧化物中 Mn 的解吸之间存在关系，这两个因素都导致了水质下降。它们还揭示了铁浓度的增加会影响森林 NDVI（绿化），这被解释为环境退化。叶绿素-a 浓度的增加（与浊度降低有关）以及河流流量的增加（负责稀释效应），似乎起到了缓解退化的作用。虽然该方法应用于特定地点，但我们的建模方法可以转化为等效的大坝故障和气候背景，帮助水资源管理当局决定采取适当的恢复解决方案。
