Pacific Northwest National Laboratory, P.O. Box 999, Richland, WA, 99352, USA.
Pacific Northwest National Laboratory, P.O. Box 999, Richland, WA, 99352, USA.
J Environ Radioact. 2022 Mar;243:106809. doi: 10.1016/j.jenvrad.2021.106809. Epub 2022 Jan 5.
A method was developed to measure trace noble gas element adsorption to the surfaces of geologic materials in the presence of a background gas that could potentially compete for surface adsorption sites. Adsorption of four noble gas elements (Ne, Ar, Kr, and Xe) at a concentration of 100 ppm in helium and nitrogen were measured on a sample of crushed tuff at 0, 15, 30, and 45 °C. In addition, Ne, Ar, Kr, and Xe at 250 ppm and 500 ppm in nitrogen at 15 °C were measured. Noble gas adsorption was found to increase with increasing atomic mass and decreasing temperature. It was also observed that the relative increase in noble gas element adsorption with decreasing temperature tends to increase with increasing atomic mass. As the noble gas concentrations in nitrogen increased, adsorption increased in a slightly non-linear fashion which could be modeled using a Freundlich isotherm. For noble gas concentrations that were ≤100 ppm Henry's Law constant were calculated.
开发了一种方法来测量在可能竞争表面吸附位的背景气体存在下，地质材料表面痕量稀有气体元素的吸附。在 0、15、30 和 45°C 下，在氦气和氮气中浓度为 100 ppm 的四种稀有气体元素（Ne、Ar、Kr 和 Xe）在粉碎的凝灰岩样品上进行了测量。此外，还在 15°C 的氮气中测量了 250 ppm 和 500 ppm 的 Ne、Ar、Kr 和 Xe。稀有气体吸附随着原子质量的增加和温度的降低而增加。还观察到，随着温度的降低，稀有气体元素吸附的相对增加趋势随着原子质量的增加而增加。随着氮气中稀有气体浓度的增加，吸附以略微非线性的方式增加，这可以使用 Freundlich 等温线来建模。对于浓度≤100 ppm 的稀有气体，计算了亨利定律常数。
