National Energy Technology Laboratory, Regional University Alliance , Pittsburgh, Pennsylvania 15236, United States.
Environ Sci Technol. 2014 Apr 15;48(8):4317-26. doi: 10.1021/es4053895. Epub 2014 Mar 31.
Systematically varying properties and reactivities have led to focused research of the environmental forensic capabilities of rare earth elements (REE). Increasing anthropogenic inputs to natural systems may permanently alter the natural signatures of REE, motivating characterization of natural REE variability. We compiled and analyzed reported dissolved REE concentration data over a wide range of natural water types (ground-, ocean, river, and lake water) and groundwater chemistries (e.g., fresh, brine, and acidic) with the goal of quantifying the extent of natural REE variability, especially for groundwater systems. Quantitative challenges presented by censored data were addressed with nonparametric distributions and regressions. Reported measurements of REE in natural waters range over nearly 10 orders of magnitude, though the majority of measurements are within 2-4 orders of magnitude, and are highly correlated with one another. Few global correlations exist among dissolved abundance and bulk solution properties in groundwater, indicating the complex nature of source-sink terms and the need for care when comparing results between studies. This collection, homogenization, and analysis of a disparate literature facilitates interstudy comparison and provides insight into the wide range of variables that influence REE geochemistry.
系统地改变性质和反应性导致了对稀土元素（REE）环境法医能力的重点研究。人为向自然系统输入的增加可能会永久改变 REE 的自然特征，促使对自然 REE 变异性进行特征描述。我们编译和分析了广泛的天然水类型（地下水、海洋水、河水和湖水）和地下水化学（如淡水、盐水和酸性水）中报告的溶解 REE 浓度数据，目的是量化自然 REE 变异性的程度，特别是地下水系统。通过非参数分布和回归解决了受限制数据带来的定量挑战。天然水中 REE 的报告测量值范围近 10 个数量级，但大多数测量值在 2-4 个数量级内，彼此高度相关。地下水溶解丰度和整体溶液性质之间几乎没有全球相关性，这表明源汇项的复杂性质以及在研究之间比较结果时需要谨慎。这种对不同文献的收集、均匀化和分析促进了研究之间的比较，并深入了解影响 REE 地球化学的广泛变量。
