Nicholas School of the Environment, Duke University, Durham, NC 27708, USA.
Nicholas School of the Environment, Duke University, Durham, NC 27708, USA.
Sci Total Environ. 2022 Dec 1;850:157971. doi: 10.1016/j.scitotenv.2022.157971. Epub 2022 Aug 11.
High concentrations of metal(loid)s in phosphate rocks and wastewater associated with phosphate mining and fertilizer production operations pose potential contamination risks to water resources. Here, we propose using Sr isotopes as a tracer to determine possible water quality impacts induced from phosphate mining and fertilizers production. We utilized a regional case study in the northeastern Negev in Israel, where salinization of groundwater and a spring have been attributed to historic leaking and contamination from an upstream phosphate mining wastewater. This study presents a comprehensive dataset of major and trace elements, combined with Sr isotope analyses of the Rotem phosphate rocks, local aquifer carbonate rocks, wastewater from phosphate operation in Mishor Rotem Industries, saline groundwater suspected to be impacted by Rotem mining activities, and two types of background groundwater from the local Judea Group aquifer. The results of this study indicate that trace elements that are enriched in phosphate wastewater were ubiquitously present in the regional and non-contaminated groundwater at the same levels as detected in the impacted waters, and thus cannot be explicitly linked to the phosphate wastewater. The Sr/Sr ratios of phosphate rocks (0.707794 ± 5 × 10) from Mishor Rotem Industries were identical to that of associated wastewater (0.707789 ± 3 × 10), indicating that the Sr isotopic fingerprint of phosphate rocks is preserved in its wastewater. The Sr/Sr (0.707949 ± 3 × 10) of the impacted saline groundwater were significantly different from those of the Rotem wastewater and the background saline groundwater, excluding phosphate mining effluents as the major source for contamination of the aquifer. Instead, the Sr/Sr ratio of the impacted water was similar to the composition of brines from the Dead Sea, which suggests that the salinization was derived primarily from industrial Dead Sea effluents with distinctive Sr isotope and geochemical fingerprints.
高浓度的金属（类）在磷酸盐矿石和与磷酸盐开采和肥料生产相关的废水中，对水资源构成潜在的污染风险。在这里，我们提出使用锶同位素作为示踪剂，以确定磷酸盐开采和肥料生产可能对水质造成的影响。我们利用以色列内盖夫东北部的一个区域案例研究，那里的地下水和泉水的盐化归因于历史上上游磷酸盐开采废水的泄漏和污染。本研究提供了一个主要和微量元素的综合数据集，并结合 Rotem 磷矿、当地含水层碳酸盐岩、Mishor Rotem 工业磷酸盐作业废水、疑似受 Rotem 采矿活动影响的咸地下水以及来自当地朱迪亚组含水层的两种类型背景地下水的锶同位素分析。研究结果表明，在区域地下水和未受污染的地下水中，磷酸盐废水中富集的微量元素普遍存在，其水平与受影响水域中检测到的水平相同，因此不能明确将其与磷酸盐废水联系起来。Mishor Rotem Industries 的磷矿（0.707794 ± 5 × 10）的 Sr/Sr 比值与相关废水（0.707789 ± 3 × 10）相同，表明磷矿的 Sr 同位素指纹在废水中得以保留。受影响的咸地下水的 Sr/Sr（0.707949 ± 3 × 10）与 Rotem 废水和背景咸地下水的 Sr/Sr 明显不同，排除了磷酸盐采矿废水是含水层污染的主要来源。相反，受影响水的 Sr/Sr 比值与死海卤水的组成相似，这表明盐化主要来自具有独特 Sr 同位素和地球化学指纹的工业死海废水。
