Escot-Espinoza Victor Manuel, Ramos-Arroyo Yann Rene, Lázaro Isabel, Montes-Avila Isidro, Carrizalez-Yañez Leticia, Briones-Gallardo Roberto
Facultad de Ingeniería, Universidad Autónoma de San Luis Potosí, Av. Dr. Manuel Nava 304, San Luis Potosí 78210, Mexico.
Departamento de Ingeniería Geomática e Hidráulica, Universidad de Guanajuato, Av. Juárez 77, Zona Centro, Guanajuato 36000, Mexico.
Toxics. 2021 Nov 15;9(11):307. doi: 10.3390/toxics9110307.
Mine wastes from the La Aurora mine in the state of Guanajuato were generated by the flotation process and placed in four tailing dumps on the local stream while the plant operated. Given that these wastes contain toxic elements, it is important to establish their impact on the quality of several surrounding natural sources of water that are considered potential drinking water supplies. This study identified four water source types, in which the contents of arsenic (As), mercury (Hg), and thallium (Tl) were exceeded, according to international guideline values for drinking water quality. The first type of aqueous sample corresponded to leachates produced by rainwater infiltration in tailings and water-mineral waste interactions. The second type corresponded to surface water along the Xichú and La Laja Streams, and the third and fourth types involved two groundwater well samples and spring samples, respectively. The Chiquito Stream was used as a reference area that had not been impacted by the mine wastes. The isotopic signatures associated with δS and δO compositions from the El Ojo de Agua spring are similar to those of the Santa María River and are different from those of the mine waste leachates. This study shows evidence of the presence of As in the El Ojo de Agua spring, which results from dissolution of secondary mineral phases that were produced by alteration of the mine wastes, which then migrated along the Xichú Stream system until reaching the spring. These As-bearing fine particles are prone to dissolution when in contact with this water source. Principal component analysis revealed that the observed As, Tl, and Hg can be attributed to weathering of the mine wastes. However, the results suggest that a natural contribution of these elements could be associated with rainwater-igneous rock interactions.
瓜纳华托州拉奥罗拉矿产生的矿山废料是通过浮选工艺产生的，在工厂运营期间被放置在当地溪流的四个尾矿堆中。鉴于这些废料含有有毒元素，确定它们对周围几种被视为潜在饮用水源的天然水源质量的影响非常重要。本研究确定了四种水源类型，根据国际饮用水质量准则值，其中砷（As）、汞（Hg）和铊（Tl）的含量超标。第一种水样对应于尾矿中雨水渗透以及水与矿物废料相互作用产生的渗滤液。第二种对应于希楚河和拉哈亚河沿岸的地表水，第三和第四种类型分别涉及两个地下水井样本和泉水样本。奇基托河被用作未受矿山废料影响的参考区域。阿瓜泉（El Ojo de Agua）的δS和δO组成的同位素特征与圣玛丽亚河相似，与矿山废料渗滤液不同。本研究表明阿瓜泉中存在砷，这是由矿山废料蚀变产生的次生矿物相溶解导致的，这些次生矿物相随后沿着希楚河水系迁移，直至到达泉水处。这些含砷细颗粒与该水源接触时容易溶解。主成分分析表明，观察到的砷、铊和汞可归因于矿山废料的风化作用。然而，结果表明这些元素的自然来源可能与雨水 - 火成岩相互作用有关。
