Soil and Water Chemistry and Trace Metal Extractability and Speciation in Wetland Soils from Illinois and South Carolina and Stream Sediments from Tennessee

Trace metals are essential for microbially-mediated biogeochemical processes occurring in anoxic wetland soils and stream bed sediments, such as denitrification, methanogenesis, and mercury methylation. Low availability of these elements may potentially inhibit key components of anaerobic carbon and nitrogen cycling and contaminant transformation. The solid-phase speciation of trace metals likely plays an important role in controlling their bioavailability. Metal speciation is well studied in contaminated soils and sediments as well as those naturally elevated in trace metals. However, less is known regarding the chemical forms of trace metals in systems having concentrations similar to geological background levels, the very settings where metal limitations may be most prevalent. We have investigated trace metal concentrations, extractability, and solid-phase speciation in three freshwater subsurface aquatic systems: marsh wetland soils, riparian wetland soils, and the sediments of a streambed. Data are provided for marsh wetland soils at Argonne National Laboratory, riparian wetland soils in the Tims Branch watershed at Savannah River National Laboratory, and stream bed sediments from East Fork Poplar Creek near Oak Ridge National Laboratory. Soil and sediment elemental abundances, mineralogy, and extractable nutrients as well as dissolved major elements, anions, trace metals, and nutrients in the overlying surface waters are provided. In addition, the results of sequential chemical extraction for the trace metals cobalt, nickel, copper, and zinc from the soils and sediment are reported as well as X-ray absorption near-edge structure (XANES) spectra in these materials are reported. To aid interpretation of these data, XANES spectra of sulfur in the soils and sediments as well as both XANES and extended X-ray absorption fine structure (EXAFS) spectra of iron in these materials are reported. The data package also includes the XANES spectra of reference standards and a potential interferent in the measurements. All data are provided in text-based CSV format with header sections indicating the data contained in each file and the corresponding units. Note that "u" is used in place of Greek lower case mu to indicate the micro prefix on units.痕量金属（trace metals）对于缺氧湿地土壤与河床沉积物中微生物介导的生物地球化学过程至关重要，例如反硝化作用（denitrification）、产甲烷作用（methanogenesis）以及汞甲基化（mercury methylation）过程。此类元素的生物有效性不足，可能会抑制厌氧碳氮循环与污染物转化过程中的关键环节。痕量金属的固相形态很可能在调控其生物有效性方面发挥关键作用。目前学界已对受污染土壤、沉积物以及天然痕量金属含量偏高的介质中的金属形态开展了充分研究。然而，对于痕量金属浓度接近地质背景值的系统——也就是金属限制效应可能最为普遍的环境——其中的痕量金属化学形态，学界的认知仍较为有限。本研究针对三类淡水地下水生系统展开了系统分析，涵盖沼泽湿地土壤、河岸湿地土壤以及河床沉积物，测定了其中的痕量金属浓度、可提取特性以及固相形态。本数据集包含阿贡国家实验室（Argonne National Laboratory）的沼泽湿地土壤、萨凡纳河国家实验室（Savannah River National Laboratory）蒂姆兹流域的河岸湿地土壤，以及橡树岭国家实验室附近的东福克波普勒溪河床沉积物的相关数据。数据集同时提供了土壤与沉积物的元素丰度、矿物组成、可提取营养盐数据，以及上覆地表水中溶解态常量元素、阴离子、痕量金属与营养盐的相关数据。此外，本数据集还报道了针对土壤与沉积物中钴、镍、铜、锌四种痕量金属的连续化学萃取实验结果，以及此类介质的X射线吸收近边结构（X-ray absorption near-edge structure, XANES）光谱数据。为便于对数据进行解读，本数据集还提供了土壤与沉积物中硫的XANES光谱，以及此类介质中铁的XANES与扩展X射线吸收精细结构（extended X-ray absorption fine structure, EXAFS）光谱数据。本数据包还包含了测量过程中所用的参考标准物质以及潜在干扰物的XANES光谱数据。所有数据均以基于文本的CSV格式存储，文件头部分标注了各文件包含的数据内容与对应单位。请注意：数据中使用字母"u"替代希腊小写μ来表示单位中的微（micro）前缀。