Chemical and physical drivers of beryllium retention in two soil endmembers
Chemical and physical drivers of beryllium retention in two soil endmembers
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DOI：
10.1016/j.scitotenv.2020.141591
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发表时间：
2021-02-01
影响因子：
9.8
通讯作者：
Willenbring, Jane K.
中科院分区：
文献类型：
--
作者：
Boschi, Vanessa;Willenbring, Jane K.
大气中高能溅射反应产生的流星体10Be和7Be通过干、湿沉降的方式沉积在地球表面，并吸附在粒子表面。在陆地上，吸附浓度的规模与沉积物的停留时间在缓慢（10Be）和快速（7Be）放射性衰变的偏移。此外，从矿物中浸出的天然9Be的量与土壤的化学风化有关。然而，以前的工作表明，土壤和河流沉积物的化学和物理性质影响铍的吸附。因此，吸附铍浓度的大小可能更能代表系统的吸附能力，而不是其侵蚀或风化历史。虽然以前的工作已经研究了影响铍吸附的土壤的物理和化学性质，这些研究要么缺乏共识，要么排除潜在的重要变量。在这项工作中，我们提供了一个彻底的检查变量先前报道的影响铍化学以及新的变量，如氮，磷和硫的浓度，以确定哪些因素最好地预测铍吸附。我们选择了两个土壤端元具有不同的组成，将它们分成不同的尺寸级，其特征在于表面积，阳离子交换容量（CEC），矿物学，硫，碳，氮和磷的浓度。我们确定，反百分比丰富的石英和CEC最好的预测铍在这些土壤中的吸附潜力。通过推导出一个模型，这两个变量的百分比吸附铍，我们能够预测我们的系统的吸附能力，并减少了约42%的误差吸附铍量由于土壤性质的差异。从这些结果中，我们提供了洞察力，为什么有不一致的文献中关于铍的环境行为的物理化学控制。(C)2020 Elsevier B.V.保留所有权利。
Meteoric 10Be and 7Be produced in the atmosphere from high-energy spallation reactions are deposited onto the Earth's surface through wet and dry deposition and are sorbed onto the surfaces of particles. On land, the sorbed concentrations scale with the residence time of sediments in a landscape-offset by slow (10Be) and fast (7Be) radioactive decay. Additionally, the amount of native 9Be, leached from minerals, correlates with the chemical weathering of soils. However, previous work has shown that chemical and physical properties of soils and river sediments affects sorption of beryllium. Therefore, the magnitude of sorbed beryllium concentrations may be more representative of the sorption capacity of the system rather than its erosional or weathering history. Although previous work has examined the physical and chemical properties of soil that influence beryllium sorption, these studies either lack consensus or exclude potentially important variables. In this work, we provide a thorough examination of variables previously reported to have influence on beryllium chemistry as well as new variables such as nitrogen, phosphorus and sulfur concentrations in order to determine which factors best predict beryllium sorption. We selected two soil endmembers with differing compositions, separated them into different size fractions, and characterized the surface area, cation exchange capacity (CEC), mineralogy, sulfur, carbon, nitrogen and phosphorus concentrations. We determined that the inverse percent abundance of quartz and the CEC best predict beryllium sorption potential in these soils. By deriving a model that relates these two variables to the percent sorbed beryllium, we were able to predict the sorption capacity of our system and reduced the error in sorbed beryllium amounts due to differences in soil properties by about 42%. From these results, we provide insight as to why there is inconsistency in the literature with regards to the physio-chemical controls on the environmental behavior of beryllium. (C) 2020 Elsevier B.V. All rights reserved.