Chemistry Department, Universidade Estadual de Londrina, Londrina, Paraná, Brazil.
Physics Department, Universidade Estadual de Londrina, Londrina, Paraná, Brazil.
Chemosphere. 2021 Nov;283:131157. doi: 10.1016/j.chemosphere.2021.131157. Epub 2021 Jun 15.
On November 5th, 2015, a mining dam spilled a huge plume of mining waste in the Doce River. Even though many studies have reported the environmental impact from the Doce River's tragedy, the transport of potentially toxic elements (PTE) by kinetic modeling to determine how long the basin takes to achieve the natural balance has not been described. Therefore, samples of sludge, sediment, and water were collected along the Doce River basin, to assess the elements' total leaching by kinetic modeling. The elements Fe, Al, Mn, Cu, Ag, Pb, Cd, and As were evaluated. An innovative mobilization factor (F) indicated that Mn, Ag, and Cd can be mobilized about 80, 89, and 57 times more than its initial concentration. Besides, in low pH, the Al and Pb ions can be mobilized. The desorption kinetics showed a lower rate constant (k) and higher initial desorption constant (h) for Mn than Cd and Ag, suggesting both high- and low-affinity interaction sites for Mn. The exponential decay demonstrated that metals can leach for months or years. Thus, the long-lasting release of metals from mining tailing waste in concentrations that endanger the ecosystem and human health makes clear the need for long-term monitoring.
2015 年 11 月 5 日，一座采矿大坝在多西河溢出了大量的采矿废物。尽管许多研究报告了多西河悲剧造成的环境影响，但通过动力学模型来确定流域需要多长时间才能达到自然平衡来运输潜在有毒元素（PTE）的情况尚未描述。因此，沿着多西河流域采集了污泥、沉积物和水样本，以通过动力学模型评估元素的总浸出率。评估了元素 Fe、Al、Mn、Cu、Ag、Pb、Cd 和 As。一个创新的迁移因子（F）表明，Mn、Ag 和 Cd 可以比其初始浓度多移动约 80、89 和 57 倍。此外，在低 pH 值下，Al 和 Pb 离子可以被迁移。解吸动力学表明，Mn 的速率常数（k）和初始解吸常数（h）均低于 Cd 和 Ag，表明 Mn 具有高亲和性和低亲和性的相互作用位点。指数衰减表明金属可以浸出数月甚至数年。因此，采矿尾矿废物中金属的持久释放浓度会危及生态系统和人类健康，这清楚地表明需要进行长期监测。
